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Attractive geology does not guarantee mining investment if a region’s policies are bad, according to mining executives surveyed in the Fraser Institute’s seventh Annual Survey of Mining Companies. Companies responsible for a combined US$642.4 million in international exploration (during 2002) rated the policy attractiveness and mineral attractiveness of mining jurisdictions around the world. Jurisdictions like Chile, Australia, Quebec and Nevada bolster their attractive geology with mining-friendly policies, the report said. These locations do well on the overall investment attractiveness index. On the other hand, jurisdictions like British Columbia and Indonesia, each with excellent geology, are hurt by their policies, which have lowered their score.

Jan 1, 2004

By Wadaw Cybulski

The problem of coal dust explosions: Basic information about the explicability of coal dust: Main parameters of the explosibility of coal dust; Main parameters of the explosibility of coal dust; Limit explosibility of coal dust and its dependence upon the basic parameters: The effect of the initiator of the explosion-on-the explosibility of coal dust: The dependence of the course of an explosion upon the distribution of coal dust in the workings, upon the dimensions of the workings, the length of zones, the direction of the development of explosions and upon the content of firedamp in the air of the workings; Con-sequences of coal dust explosions; The ways of suppressing the danger of coal dust explosions; Stopping the developed coal dust explosions; The explosibility and explosions of lignite dust of xylite structure

Jan 1, 1975

By Brenda M. Dixon

A matrix analysis of the differences between the camps and communities associated with the Britannia Mine is used to develop an analytical tool. The tool is intended to assist the mining industry as it embraces the many facets of sustainable development. A case study is used to support the identification of key factors that may predict the sustainability of a new mine town. Sustainable communities, like Britannia Beach, are discussed in the context of three pillars of sustainability: value of mining products to society; creating wealth; and, environmental integrity. A sustainable mine town may be viewed as a socio-economic asset as well as an asset to the mining industry.

May 1, 2006

By E. C. Potter

FUEL-OIL was first substituted for coal at these works in September, 1888. It was first applied in the converting-department to the battery of boilers, consisting of 14 tubular boilers, 16 feet in length by 5 feet in diameter. To operate these boilers with coal for 24 hours required 14 strikers, 3 ash-wheelers, 6 men unloading coal, and 2 water-tenders, making a total of 25 men. With fuel-oil the same boilers require for the same period 2 water-tenders and 4 men to attend to the burners, making a total of 6 men. This gives a saving of 19 men, which, at an average of $2 per day each, amounts to $38 per day. Comparing the consumption of oil with that of coal, we find that for the week ending January 5, 1889, with an ingot output of 6403 tons, 2731 barrels of fuel-oil were used as against a necessary consumption of coal for the same work of 848 tons, showing 3.22 barrels of fuel-oil to be equivalent to one ton of Indiana block-coal. Figuring oil at 60 cents per barrel, and coal at $2.15 per ton, we have as the cost of oil $1.93, as against $2.15 for its equivalent in coal. In December, 1888, the rail-mill battery of 26 boilers, of the same dimensions as those in the converting-department, was equipped for fuel-oil. For the week ending January 5, 1889, with a rail out-put of 5208 tons, 5987 barrels of oil were consumed, as against a necessary consumption of coal, to do the same work, of 1805 tons, showing 3.31 barrels of fuel-oil to be equivalent to one ton of Indiana block-coal, which at the costs named above would show $1.98 worth of fuel-oil to he equal to $2.15 worth of coal. The labor required to operate the rail-mill boilers for 24 hours, with coal as fuel,is: 26 stokers, 4 water-tenders, 6 ash-wheelers, 12 men unloading coal; total, 48 men. With oil as fuel, the same work requires 4 water-tenders and 6 men to attend to the burners; total, 10 men; a saving over coal of 38 men in 24 hours, which, at an average price of $2 per day, would be $76 per day. In the brief experience we have had with oil as fuel, we find that the efficiency of the boilers is somewhat increased and the repairs are

Jan 1, 1889

By John J. Baz-Dresch

Catalyzed diesel particulate filters (CDPF's) reduce the concentration of diesel particulate matter (DPM) and may reduce the emissions of carbon monoxide (CO) and hydrocarbons (HC) in diesel exhaust. Asamera Minerals' Cannon Mine first installed CDPF's in 1987, and currently has 12 diesel-powered vehicles equipped with CDPF's. The Cannon Mine and the U.S. Bureau of Mines collaborated to evaluate the durability and performance of a CDPF. One of the CDPF's used at the mine was periodically evaluated in the USBM's diesel emissions laboratory after 839, 1,584, and 2,881 h of in-mine service. The objectives of this report are to present results from the USBM's evaluation of this CDPF, to describe the Cannon Mine's experience and cost analysis of using CDPF's, and to make recommendations for the future use of CDPF's. CDPF's improve air quality at the Cannon Mine, but they frequently become plugged and are subject to excessive mechanical shocks and stress, shortening their useful life. Mine records indicate that CDPF's account for 0.8 to 4.9 pct of the vehicles' operating cost at the lVine. CDPF life to date has ranged from 1,671 h to more than 5,992 h. Laboratory tests of the CDPF determined that DPM removal efficiency decreased and regeneration temperature increased over time.

Jan 1, 2010

By W. Collingwood

As open pit mines continue to grow deeper and productivity continues to increase, the management of respirable dust and noxious gases can become a challenge. The natural wind flow in open pit mines is often recirculatory. This recirculation traps dust and gases in deep open pit mines. This problem is particularly acute in high latitude open pit mines due to a phenomenon known as an atmospheric inversion. In the winter, arctic and subarctic regions experience short days and long nights. This deficit of solar radiation creates a situation in which cold, still air accumulates near the bottom of the pit. In open pit mines, this can result in unhealthy accumulations of gases and other contaminants in the open pit mines. In this study, the natural wind flow patterns in and around open pit mines were investigated using a computational fluid dynamics (CFD) program. Two dimensional models were created for a variety of pit geometries. The effect of depth, slope angle, and wind speed on the recirculation pattern in the pit was examined.

Jan 1, 2011

By A. C. Wilson

In 1991, local prospector C. ?Mickey? Clement recovered at least three alluvial diamonds from the Michipicoten River. Two of these stones were sent to the Department of Mineralogy, Royal Ontario Museum, where they were identified as industrial grade diamonds with weights of 1.05 and 1.13 carats. Both stones were described as frosted and graphite-inclusion riddled. In 1995, prospector Sandor Surmacz and geologist Marcelle Hauseux discovered diamonds in bedrock approximately 20 km north of the Michipicoten River. An 18.1-kg bulk sample of a xenolith-rich lamprophyre, taken from an outcrop at the side of the Trans Canada Highway north of Wawa, yielded 1 macro diamond and 5 micro diamonds. All but one was gem quality (Sage 2000). Since then, more than 36 occurrences of diamonds in bedrock have been reported in an approximately 30 km2 area centred 20 km north of the town of Wawa. The occurrences are hosted within a sequence of unusual, Archean-aged, heterolithic breccias previously considered to have no economic significance. Ten kimberlite occurrences also have been confirmed in the Michipicoten greenstone belt in the last 5 years. Two of these kimberlites are diamondiferous. To date, expenditures on property acquisition and diamond exploration in the Wawa are estimated at $120 million (CAN). This paper summarizes the geological observations made on these occurrences and discusses including the relationship between the occurrences and the regional geology.

May 1, 2003

By Wilford S. Wright, Harold E. Heide, Robert S. Sanford

"INTRODUCTION The United States production of tin has always been negligible, and domestic requirements have been met almost entirely by imports. The advent of war in Europe in 1939 brought a threat to our foreign source of supply, and steps were taken by Congress to forestall shortages of tin and other metals. By authority of the Strategic Minerals Act, passed by Congress in 1939, the Bureau of Mines and Geological Survey conducted investigations of domestic tin deposits.An examination of Alaska deposits was undertaken in 1940 and 1941 by J. B. Mertie, Jr., and Robert R. Coats of the Geological Survey.H. B. Heide conducted a preliminary examination of lode and placer-tin deposits at Cape Mountain in 1942, which was followed in 1943 and 1944 by a program of exploration by churn drilling in the placer area and trenching and sampling the lode deposits.Placer tin, found at the head of Goodwin Gulch, Cape Creek, First Chance Creek, and Boulder Creek, indicates that the mineral was derived from the vicinity of lode cassiterite occurrences on Cape Mountain. Placer tin led to the discovery of at least one, cassiterite vein by the Geological Survey and the Bureau of Mines."

Dec 1, 1946

By T. Weatherwax

As part of a strategic research initiative at UBC to design and evaluate integrated underground mining and mineral processing systems, work has been done to determine how to utilize the coarse rejects of pre-concentration in the underground environment. An amenability study for nine orebodies from four of Xstrata Nickel?s Ontario operations evaluated both processing and waste disposal methods. The utilization of the rejects as a high quality backfill with minimal binder requirements has been identified as the preferred disposal method. Fill mixes utilizing the rejects in combination with classified tailings, full tailings, and cement were developed based on the geotechnical properties of the rejects. The mix designs were examined for both strength and rheological properties. The paper will present the results of the pre-concentration testwork, the design and strength testing of various mix designs for rejects from the nine ores and presents a conceptual design for an underground pre-concentration system based on this test work.

Jan 1, 2008

By R. B. Ngenda

The ?Kolwezi Zinc Plant?, in French ?Usines à Zinc de Kolwezi? (UZK), has produced about 910 000 dry metric tons of residues during the hydrometallurgical treatment of calcines from sulphide zinc concentrates. The zinc hydro plant residues contain on average 19.47% Zn, 2.7% Cu, 2.1% Pb, 26.6% Fe, 0.12% Cd, 0.39% As, 157ppm Ag, 447.8 ppm Ga, 475.4 ppm Ge, etc. This material was dumped in five ponds in the vicinity of the plant. The high Fe content in the ore concentrates induced important conversion of some of zinc and copper into ferrites during the roasting process. Those ferrites are very stable compounds, which are difficult to leach with dilute sulphuric acid solution. Therefore, they mainly report to the leaching residues. Hot leaching has been successfully applied to the treatment of zinc hydro plant residues. The method, however, presents the disadvantage of simultaneously dissolving iron(Fe). It is then necessary to remove an important iron quantity from solution prior to zinc and other metals recovery.

Jan 1, 2009

By K J. Ward, C N. Hatton, J Scalia IV, C A. Bareither, D L. Spencer

The mining industry is experiencing change in the governance of tailings facilities (TFs). Guidance and regulations across many jurisdictions contribute to this amorphous change. The Canadian Dam Association, Mining Association of Canada, Australian National Committee on Large Dams, and the Global Industry Standard on Tailings Management, produced by the International Council on Mining and Metals, are establishing guidelines for more rigorous industry governance. Evolving guidance regarding TFs is developing concurrently with a shortage of experienced tailings engineers, which adversely affects the resource base available to support new governance. This paper presents an updated semi-quantitative estimate of the impending resource shortage of qualified tailings professionals. Updates are provided herein for the estimated number of TFs worldwide, which included available data on active and inactive TFs, as well as the estimated labor resources required to service these facilities. The tailings labor shortage is discussed in the context of academic and professional training currently available to increase the quantity of trained personnel. This paper represents a discrete moment in time as contributions to the available information and inventories accessed continue to improve, but as of today are incomplete. However, the data and information included provide insight into the resource deficiencies currently within our profession, training and education opportunities to address those resource deficiencies, and a snapshot of a recent professional training course offered on mine tailings.

Jul 1, 2021

By Robert Labbe

The final tunnel lining for this project involved pumping vast quantities of concrete over large distances under the extremely busy streets of lower Manhattan. Approximately 68,000 cubic meters (89,000 cubic yards) were pumped from various locations over 152 meters (500 feet) below ground (Figure 1) to create nearly 14.5 kilometers (9 miles) of 3.05 meter (10 foot) diameter tunnel. Total distances pumped exceeded 1,645 meters (5,400 feet) horizontally after a vertical difference of over 152 meters (500 feet). The urban setting of the operation, coupled with the long distances over which concrete was pumped, created many problems which had to be dealt with along the way. A three-shift labor operation was implemented to allow sequential pouring of tunnel sections nearly every day. The fine tuning of the mix design was critical to make this operation successful.

By Frank E. Chase

The Harris No. 1 Mine, located in Boone County, WV, has been longwalling the Eagle Coalbed for over 30 years. Harris has experienced numerous interactions associated with the extensive room-and-pillar and longwall mining operations which have been conducted in the overlying No. 2 Gas Coalbed. The problems have included roof falls, excessive rib sloughage, and gateroad and bleeder entry closure. A detailed evaluation of the multiple seam experiences at Harris No. 1 Mine was conducted as part of the National Institute for Occupational Safety and Health (NIOSH) nation-wide multiple seam mining case history data base. One observation from the Harris gateroad case histories was that smaller, critically loaded, upper seam pillars seemed to cause more severe ground conditions than did wider pillars. The LaModel program was used to investigate this supposition, and the results confirmed that "critical" sized pillars do transmit the highest amounts of stress to adjacent seams. In addition, the data suggest that the probability of a major multiple seam mining interaction increases when the depth of cover is 1,000 ft or greater and when the Eagle seam pillars have a Analysis of Longwall Pillar stability factor less than 1.50.

Jan 1, 2005

Using DEM to Model Industrial Banana Screens

Sep 13, 2010

By M. N. Brodie

"The ability to adjust the speed of a SAG mill offers benefits to the process and to equipment maintenance. It can be provided with some slight effect on availability ranging from somewhat enhanced to somewhat reduced, depending on the particular equipment that is used. Several techniques have been developed for monitoring the magnitude of the contained charge, and several algorithms have been used to control mill feed rate and mill speed. The various benefits and the means by which they can be realized are examined and compared. Reasons for Variable SpeedProcess RequirementsThe recovery of minerals from ore is dependent on particle size and residence time in process. Separation in a given plant is most efficient at a particular rate and a particular size (e.g., 80% minus 200 mesh). If the particle size increases, less mineral will be liberated. If the particle size is significantly reduced, the process of choice may not be able to effect separation, and power, media, and maintenance costs would be increased.If a SAG mill-ball mill combination delivers the desired throughput at the correct size for efficient separation when processing ore of the design hardness, some adjustment must be made to maintain this condition when the ore changes. The processing of ore softer than design will result in overgrinding, unless:• the throughput is increased inversely to the change in hardness which lowers recovery by overloading the separation facilities;• or the SAG mill feed rate remains constant, but the speed is reduced to feed coarser material to the ball mill for finish grinding to the desired size.There is also the effect of changing milldiameter to consider. A nominal 36 ft diameter SAG mill will have an effective diameter of 35 ft with new liners and 35 ft 6 in. with worn liners. A mill designed to operate at 0.76 p.u. (per unit) of critical speed with new liners (9.84 rpm) will be changed to 0.765 p.u. with worn liners. If 0.76 p.u. is the desired value, the mill speed should be reduced to 9.77 rpm."

Jan 1, 2003

By E. P. Youngman

Zirconium, formerly distinctly a rare element, is rapidly becom- ing of rather extensive commercial importance. Economic features of the zirconium industry, together with general information regarding the metal and its compounds, are discussed in a separate paper, to which this paper is a supplement. In addition to giving a brief discussion of the four or five de- posits that so far have proved to be commercial sources of the element, this circular summarizes available data (including some hitherto unpub lished material from the files of the Bureau of Mines) upon other occur- rences, including many of scientific interest only, of the two commercial. minerals, zircon and baddeleyite, and also data upon some of the minor minerals, such as eudyalite and cyrtolite, which have attracted addition- al interest in recent years because they are frequently richer in hafnium than the more common zirconium minerals.

Jun 1, 1931

By H. O. Hofman

WITH the exception of lead sulphate, all common metallic sulphates are completely decomposed upon heating into metallic oxide, sulphur trioxide, sulphur dioxide and oxygen. Some give up their trioxide readily at a low temperature, others require considerable heat and much time to be completely freed from sulphur. Kerl in 1881 arranged the principal metallic sulphates as they are decomposed by a rising temperature in the following order: silver, iron, copper, zinc, nickel, cobalt, manganese and lead, lead sulphate being decomposed only slightly at a white heat. The researches of Bradford, published in 1903, show, however, that ferrous sulphate is decom¬posed at 590° C., cupric sulphate at G53° C. and argentic sulphate at 1,095° C. By the present investigation it will be seen that zinc sulphate is decomposed at 739° C. As far then as our present knowledge goes, the order in which the decomposition of the leading metallic sulphates takes place is the one given in Table I.

Jan 1, 1905

By George S. Rice

"""To prevent the propagation of mine explosions, the Bureau of Mines, Department of Commerce, recommends rock-dusting all coal mines, except anthracite mines, in every part, whether in damp or dry condition. It also recom¬mends that rock-dust barriers be used to sectionalize the mine as additional defense; but these should not be regarded as a substitute for generalized rock-dusting."" (Mine safety decision, No. 5, April 7, 1927.)The purposes of this circular are to present concisely the requirements for effective rock-dusting of coal mines in order to prevent propagation of mine explosions, and to point out the principal related facts on explosibility of coal dusts and mixed coal-mine dusts, as determined by extensive testing in the Experimental Mine of the Bureau of Mines. study of these principal facts on coal-dust explosibility in conjunction with the recommendations for rock-dusting, should help to make clear to mine operators and others concerned the necessity for systematic rock-dusting in all coal mines except anthracite mines, and the futility of inadequate or sporadic rock dusting.The descriptions of nearly 1000 explosion tests in the Experimental Mine are available in a forth-coming bulletin2 and in earlier publications.3For detailed specifications as to the kind of rock-dust, amount to use, where to be applied, and method of sampling and testing, the reader is referred to Bureau of Mines Serial 26064, and American Engineering Standard Committee ""Recommended American Practice for Rock-Dusting Coal Mines"" quoted in Bureau of Mines Information Circular No. 60305.Summary of Specifications for Rock-Dusting1. Mines to be rock-dustedAll coal mines, except anthracite mines, should be rock-dusted.2. Extent of rock-dustingAll open accessible parts of a coal mine should be rock-dusted, including slopes, entries, cross,-cuts, and rooms, headings and pillar workings to within at least 50 feet of the face.3 Amount of rock-dustingAfter cleaning up the coal dust as thoroughly as practicable, sufficient rock-dust should be used to have the mixture of remaining coal-dust plus the rock-dust in any zone contain 65 per cent or more of inert or noncombustible matter. First dusting may require 3 pounds to 5 pounds per linear foot of passageway.4. When to rock-dust In any zone or section (made by dividing the mine for rock-dusting purposes) when the incombustible content falls to 55 per cent, that section should be re-rock-dusted so as to bring the incombustible content well above 65 per cent."

Jun 1, 1927

By P. E. Hand

Coal is a complex heterogeneous commodity that can be mined in a number of ways and needs to be processed to a homogeneous quality that satisfies the customer?s requirements, while attempting to maximize revenues. Only a small proportion of coal is suitable for metallurgical use. Export coals cover a wide range of qualities and some coals can be used optimally in the raw state for energy production. Critical quality parameters vary and can be a combination of heat value, ash, volatiles, sulphur, phosphorus, sizing, amongst others. The level of beneficiation is generally dictated by the washability of the coal, mining contamination, and the target product quality. The steps in the coal chain covered in this paper comprise exploration, mining selections, production, the washing process, and product delivery. Many points of sampling are needed to maximize yield at the correct quality, and some of these will be described in the paper. Keywords coal chain, coal beneficiation, sampling.

Jan 1, 2014

By Tim O’Neil

The earthmover tire shortage has been a case of bust and boom for the tire industry. Tire producers were unwilling to invest ahead of the mining boom. In their defense, though, the metals sector of the mining industry tends to be cyclic, tire manufacturers are not prescient. Until two years ago, low tire demand depressed prices. The incentive to invest in new, big-tire capacity was almost nonexistent, according to Prashant Prabhu, president of Michelin Earthmover Tire worldwide. “There has been very poor anticipation or a miscaluation of the amplitude of the (tire) demand on the part of just about everybody,” said Prabhu. What a turnaround. The earthmover tire market has grown by 30 percent over the past two years. Now there are not enough earth-mover tires and likely won’t be for the next two years. Goodyear said it was offering customers bias-ply tires when it could not supply enough radial-ply tires. Komatsu said it lost equipment sales because it could not provide the tires that customers requested. Volvo and Caterpillar said they are delivering some vehicles without tires, either promising tires later or leaving the customers – mine operators – to find their own rubber.

Jan 1, 2006